When Bernie Madoff died on April 14 in prison, it was high blood pressure and kidney failure that did him in, according to a copy of his death certificate obtained by TMZ. The Ponzi scheme king’s death certificate lists hypertension, atherosclerotic cardiovascular disease (a heart condition caused by untreated high blood pressure), and chronic kidney disease as the causes of his death. His kidneys had reportedly been in sharp decline for more than eight years. He had been serving a 150-year sentence in North Carolina after being convicted of running the biggest Ponzi scheme in history, worth more than $64 billion.